Published on: 2015-03-18T22:53:32+00:00
In a Bitcoin email list post on March 18, 2015, a user named Dennis Sullivan introduced a proposal called "transaction locking". This proposal claimed to enable the acceptance of 0-conf (zero confirmation) transactions with a guarantee that they will be mined. However, Sullivan expressed skepticism about the system, noting the absence of prior discussion on the mailing list.The transaction locking scheme operates by broadcasting an InstantX transaction that spends specific outputs in Darkcoin. Certain nodes then sign a message that locks this transaction in the mempool, preventing double-spending of its inputs. All nodes are instructed to reject conflicting transactions and remove any existing ones in the mempool that conflict with the locked transaction.Once a transaction obtains consensus lock across multiple nodes in the mempool, it becomes guaranteed to be mined since it cannot be double-spent. Miners are unable to mine a double spend of the consensus-locked transaction. However, Sullivan highlights a potential attack vector that could lead to block rejections and potential network forks.To provide further insight into the proposal, Sullivan shares a link to a paper that provides a comprehensive explanation of the transaction locking concept. He also discusses potential weaknesses of the proposal, such as vulnerability to sybil attacks, Finney attacks, and defecting miners. Additionally, he emphasizes that while low-value transactions may tolerate the associated risks, larger value transactions pose a greater risk of making oneself a target.Overall, Sullivan's introductory email seeks opinions on the transaction locking proposal, expresses doubt about its effectiveness, and raises concerns about potential weaknesses and attack vectors.
Updated on: 2023-08-01T12:10:38.613919+00:00